I cut the top off of a electric water heater (80 gallon marathon) and just wired it for 110 volt, even though it was a 220volt with a 4500 watt element. It took about 7 hours to go from 52 degree water to 150 degree. The original thermostat kept it with in about 5 degrees and we did 76 birds in 1 hour 45 minutes. You can plug into ground fault line for protection. A 20 amp 110 volt circuit ran the heater, and a 1 horse power whizbang inspired plucker with out problems. Cost of heater about $10 for wiring. Heater free from landfill. I also made a lid of 2 inch dense styrofoam to hold heat in while heating, and between birds. I scald 2 at a time, then into the plucker. A 52 gallon heater will work also, just may be a little slower because of volume of water. Also if you have a plucker you already have the electricity there. I thought about propane for convenience but this works great for me.